The invention is in the field of multiple photoflash lamp units, such as flashcubes and planar arrays.
U.S. Pat. Nos. 3,598,984 to Stanley Slomski and 3,598,985 to John Harnden and William Kornrumpf disclose a multiple flash array having first and second groups of flash lamps and reflectors facing in mutually opposite directions. The array is plugged into the camera whereby the first group of lamps faces frontwardly and is connected for the lamps of that group to be flashed. When these lamps have been flashed, the array is turned around and the lamps of the second group face frontwardly and are connected to be flashed. The lamps usually are flashed one at a time; however, a plurality of lamps can be flashed simultaneously if more light is desired.
The above-referenced patent application of Kurt Weber discloses a multiple flash lamp unit that can be connected to a camera in different orientations in each of which a different group of the flash lamps is relatively farther from the camera lens axis than are the other lamps of the unit. The lamps and electrical circuitry are arranged so that in any of the orientations of the unit with respect to the camera, only the group of lamps relatively further from the lens axis can be flashed. The purpose of such an arrangement is to position the "active" group of flash lamps farther above the camera lens, in order to reduce the possibility of a "redeye" effect that causes the pupils of a person's eyes to appear red to pink in flash pictures taken when the flash lamp is close to the camera lens.
The above-referenced Blount patent application discloses a multiple-group of lamp type of flash unit having an additional terminal for causing electrical shorting of the group of lamps that are not to be flashed in each orientation of the unit.
Each of the above-referenced multiple flash lamp units has, in a preferred embodiment, a plug-in connector tab provided with a plurality of electrical connection terminals in the form of conductive stripes printed on or otherwise attached to the connector tab. The various connector terminals are connected to individual lamps or to sequential firing circuitry interconnected with lamps in the unit. Such flash units, and particularly if they employ high voltage types of flash lamps which are flashed by a high voltage pulse (1000 or 2000 volts, for example) of low current energy, are prone to electrostatic firing of one or more lamps if a connection terminal is touched by a person or object having an electrostatic charge. Such undesirable accidental flashing of lamps can also occur if the flash unit housing, which usually is made of a plastic material, acquires an electrostatic charge and a connector terminal is touched. The problem can also occur, and can be more severe, if both the plastic housing and the person or object touching a connection terminal are electrostatically charged with relatively opposite polarities. A similarly severe situation can occur when a person holds the unit at one connector while handing it to another person who grasps it by the other connector, and also when holding the unit at one connector while plugging the other connector into a camera socket.